Selecting And Installing 4WD Airbag Suspension

Steve Cassano — 15 April 2020
Incorporating air-bags into your car's suspension can set you up to lug variable loads on your adventures.

I recall my very first time camping, decades ago. A mate and I hired a Suzuki LJ50 2-stroke 4WD and went exploring Fraser Island. To say we knew nothing about 4WDing or camping is an understatement. 

We had the basics: one set of clothes each that we wore for the whole five days; a flappy canvas tent; ratty sleeping bags; a good old kero lamp; a few basic cooking things; and cans of what I still remember as pretty awful stuff. Even though we were travelling lightly, after all the Suzi was just 500cc, we had a lot of fun, at a time when there were hardly any restrictions or facilities for that matter.

Fast forward a few decades and it seems that I, like many of you, now need more stuff. More stuff seems to make life easier, extends the places we visit and the amount of time able to be spent in the outback.


Of course, bringing more stuff along, whether it’s in the back of your wagon or loaded in your trailer, places a lot of strain on a vehicle’s components and affects the way the vehicle handles, especially when towing.

This column has spoken in the past about the importance of setting up your vehicle’s suspension and choosing correct tyres for the purpose, as a basic minimum, before venturing into the vast expanses of Australia.

This suspension and tyre focus should be a key consideration over and above whether or not vehicles have had their suspension upgraded or are designed to meet a certain bespoke criteria for a particular owner’s ambitions. I’d hazard a guess most people use their 4WD for multiple purposes. 

Sometimes it may be devoid of load, running to the shops and back, and other times loaded to the brim with family, camping or holiday paraphernalia. 

It’s challenging to have a suspension setup that’s perfect for all circumstances. Though there is a simple way to assist a vehicle when it’s loaded-up or pulling a heavy trailer, while protecting the vehicle’s integrity, ride quality, handling and safety. 


I had just finished installing a new suspension lift, which certainly improved the handling, articulation, clearance and, dare I say, looks. I’m hoping this year to undertake more towing as I now seem to carry more stuff. I’m liking my creature comforts more and more as time rolls on. Tents and swags are becoming less welcome as the old back ages. 

I knew from experience that when I’d hitched up a moderately weighted camper, it impacted the way the whole rig stood, with a notable sag of the rear suspension. I also felt the handling, braking and steering didn’t quite feel right or comfortable.


I began looking for solutions that would keep my Jeep level and not sag in the rear, nor adversely impact the vehicle on-road or offroad but which could safely handle a camper in tow or a heavily loaded cargo bay. 

It’s important to note that I was not looking to increase the vehicle’s GVM, or raise the vehicle’s towing limit or its set height.

With a little research online, I came across AirBag Man, a 20-year Australian family-owned business based at Brendale in Sunny Queensland. 

AirBag Man supplies all manner of air suspension solutions for vans and hundreds of different vehicles and trucks, so a quick email sent and reply received had us on each other’s radar. They asked me several pertinent questions about my vehicle, my 4WD intentions and, most importantly, about the suspension.  While  AirBag Man carries off-the-shelf stock for many 4WDs with standard suspension, I told them I had lifted the vehicle using a lift kit new on the market, which meant, in my case, a different approach was needed. You see, I knew that fitting airbags in the rear is a D.I.Y. challenge and initially thought it would be a major job removing everything and then, after installation, putting everything back in place – but nothing could have been further from the truth. Well, in my relatively straightforward install scenario it was (see later installation rundown), but apparently other model 4WDs may require following a more complicated process. Anyone going down this path is advised to perform their own specific due diligence.

To ensure I received the correct solution for my Jeep’s particular modification, Jacob and Aaron at AirBag Man, who had continually kept me in the loop, initially forwarded a very simple template for me to fill in that ensured they supplied the right parts appropriate to specification. 

It’s vitally important when ordering online to be overtly fastidious with online specification communication processes. In this case, to ensure correct delivery of parts, I needed a measuring tape, although a digital-vernier would’ve been handy and more accurate. If the online specification process ever becomes confusing or complicated, you should cease immediately and simply pick up the phone to sort out the confusion. Ideally the process should be logical and straightforward to complete. For me, it meant crawling under the rear of the Jeep while the vehicle was on level ground and at standard ride and weight.

At AirBag Man’s suggestion I also included several images to give them as much practical information as possible, which I emailed to them the next day.


Aaron contacted me a few days later and advised that he had consulted with their engineering department and the kit was nearly ready to ship. So far I’d been impressed with their communication and even more so when the parcel arrived the next day. A great start.

The kit arrived in a solid box within a box and inside was a nice fan-out folder with instructions and other paperwork as well as, plus two blue airbags, two protective sleeves, two hose clamps, a role of protected air-line, a bag of air-line attachments, a stainless bracket and a handy cutting tool to ensure all installation cuts were straight. Also, specifically for my Jeep, was an exhaust shield to protect the polyurethane bags from any emitted heat — a nice touch.


In my case, as would be with many other wagons, the airbags are placed inside the rear coils. Leaf sprung vehicles are a different set-up but still a simple procedure from what I’ve read.

The beauty of it all is that to install my airbags inside the coil sprung vehicle, I didn’t need any special skills or major tools except for a good-size jack. The hard part, if you can call it that, is deciding where to place the inflating/deflating point and safely routing the air lines.

To begin, I placed the jack under the rear chassis and lifted the vehicle a fair bit. There was no need to raise the tyres off the ground. This results in the coil expanding, thus providing easier access to insert the bag between rings.


There may be cases with some coils (due to their tight wounding) that don’t give you the flexibility to insert the bags through the coils while still on the vehicle. In these instances, the job may require removal of each coil, usually by disconnecting sway bar links and lower shock mounts to allow further droop. If the vehicle has bump stops within the coil, then there will be more steps to undertake. AirBag Man will happily supply the correct parts and procedure for your situation.

Luckily the Jeep’s simplicity foregoes the need to remove the coils but still requires pushing and shoving the coil in place to ensure the sleeves, top protective disk and airline are correctly set.


1: After slipping on the protective sleeves, I took one end of the airline, used the supplied cutting tool to make a clean cut and then inserted it in the valve of the bag, you should feel a positive snap. Make sure the protective split conduit runs right up to the valve. 

2: I then routed the line through the protective disk, via about the middle of the coil, then out the top gap of the coil mount. 

3: Next, to ease the insertion of the bag, disk and air line through the coil, I squashed the bag as much as I could and temporarily blocked the other end of the airline with the supplied red stopper to prevent air being sucked back in. 

4: After a few pushes and prods, the bag slipped through the coil and was quickly massaged into place. I then removed the little red stopper, which returned the bag to its normal state. Next I checked for proper alignment and that nothing was out of place. Once satisfied, I routed the air line towards my chosen inflation point. I chose the rear bumper as it seemed a convenient and easily accessible spot (though I’m thinking I may change it in the future to a more protected location).

5: I drilled two 8mm holes through the plastic bumper which would accommodate the two valve stems (AirBag included a stainless bracket for mounting the valves). 

6: Once I felt comfortable with the route, I again used the cutting tool to ensure the air-line’s integrity, leaving a little slack for flexibility. I then inserted the freshly cut end into the rear of the valve stem, feeling for that assuring snap signalling that it was inserted correctly. 

The other airbag was much the same, with just a different route for the air-line. 

I had plenty of thoughts and test routing before I settled on both air-line paths. Once the air-lines were done, I pushed the valves through my drilled holes and, using the supplied stainless washers and nuts, secured them in place using a 12mm spanner. 

I had routed the lines away from sharp or heat sensitive areas and to eliminate any snagging on errant debris that could damage lines.

7: The last step was placing the supplied heat shield near the left airbag as the coil sat close to the exhaust. 

It’s worth noting that gaps could change as the vehicle articulates but, in my case, I anticipate this to be minimal. The metal shield is easily malleable and the two supplied clamps make light work of attaching it to the exhaust-pipe close to the bag.


One thing I did forget to mention was testing for leaks. My way was to inflate both bags to the recommended maximum, spray some soapy water and look for bubbles. If bubbles appear, then remove air-line, re-cut and re-test. For extra surety, I decided to inflate to maximum and leave everything overnight to check for slow leaks. Luckily all was fine. It took mere seconds to inflate the bags using my on-board compressor. Though I did find the valve stems needed some persuasion for the air-chuck to click on.

The whole task took less than two hours and was as straightforward as these types of things get. The main bulk of work was done in the clear communication at the outset. After this, it was all simply about following instructions. 

The overall quality and service received was excellent and I look forward to now towing in a safer and more confident manner. 

Happy Wheeling.


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